While occupational respiratory diseases inflict a severe toll on our national workforce, existing exposure assessment methods for many respiratory hazards lack sufficient detection sensitivity, preventing the practicing industrial hygienist from determining whether a hazard even exists. The goal of this research is to design a high flow sampling device engineered to assess inhalable aerosol hazards in the workplace in a physiologically relevant fashion. This device will extend overall method detection limits by considerably increasing sampler flowrate. The design will be inexpensive and readily-integrated into the commonly used 37-mm filter cassette. Because of its low cost, accuracy, ease-of-use, and adaptability, this device will have widespread application, especially in developing countries where exposure assessment resources and budgets are limited. Such widespread use was a major design goal for this technology, as increased use of an accurate exposure assessment technology will ultimately result in increased protection of worker health on a national and global scale. There are 3 specific aims for this project. First, to design an inexpensive, modular sampling head that (a) interfaces with a standard 37-mm cassette, (b) operates at a high rate of airflow, 10 Lpm, and (c) meets the criteria for inhalable sampling set by the American Conference of Governmental Industrial Hygienists/International Standards Organization. This high-flow design will proceed from a wide body of research on existing low-flow inhalable devices. Second, to evaluate sampler performance using computational fluid dynamic modeling and to refine the prototype design based on results from these tests. Third, to validate the refined design through laboratory tests in a wind tunnel and field tests in actual occupational environments. [unreadable] [unreadable] [unreadable]